The results obtained in the treatment of obesity in the out patient department of the Nutrition Unit of "La Paz" hospital during the first 6 years of experience were analyzed. To this end, different aspects of the treatment of obesity were studied in a successive manner. The first approach prospectively compared the results obtained with individual or group health care education (HCE); with no statistically significant differences being found. Before analyzing the results obtained with the different treatments, one notes a high rate of abandonment (65%). One sees that the global weight lost is statistically significant (7%). The amount of weight los differs depending on the degree of obesity (measured by the Body Mass Index): grade I and II obesities lost the same percentage of weight (7%), grade III lost 8% and grade IV is the grade that loses the most, 12%. Keeping in mind the treatment modality used, the results are as follows: both the diet alone and the diet in association with health care education in a group, achieve a weight loss of 7%, modified fasting yields 6%, adding drugs to the diet achieves a loss of 11% and the most effective is bariatric surgery with a loss of 18%.